Monoazo dyestuff and process of making same.



UNITED STATES PATENT ora on.-

HUGO GELDERMANN, OF GROSS-LICHTERFELDE-OST, BERLIN, GE

ACTIEN GESELLSCHAFT FlIlR AN ILIN FABRIKATION, OF BEfiIN, GERMANY.

MoNoAzo nYEs'rUrr AND rnocnss or MAKING seam.

No Drawing.

To all whom it. may concern:

Be it known that I, HUGO GELDERMANN, a subject of the German Emperor, residing at Gross Lichterfelde Ost, Berlin, Germany, (my post-office address being Grabenstrasse 12, Gross-Liehterfelde-Ost, Berlin), have invented certain new and useful Improvements in New Monoazo Dyestufl" and Processes of Making the Same, of which the following is a specification.

My present invention relates to improvements in the manufacture of yellow monoazo dyestuffs for W001 and is based on the observation that by dia'zotizing para-chloranilinmeta-sulfonic acid and combining the dia zocom'pound thus prepared with 1-phenyl-3- methyl-5-pyrazolon a very valuable dyestufi' is obtained, which new. coloring matter dyes wool from an acid bath containing sulfuric acid clear and: intense yellow tints of a good fastness' which are moreespecially very fast to light.

The following example serves to illustrate my invention, the parts being by Weight:

Example: 20.7 parts of para-chloranilinmeta-sulfonic acid (NH :61 :SO H=1-:4E:3) are diazotized in the usua l manner by means of 7 parts of sodium nitrite and of 30 parts of concentrated hydrochloric acid (2022 B. specific gravity). The 'diazo solution thus obtained is allowed to run into a solution of 1-phenyl-3-methy1e5-pyrazolon which is prepared by dissolving 18 parts of this body in water by means of the calculated proportion of soda-lye and which solution is added with such aquantity of sodium carbonate as to warrantalkaline reaction to the end of the reaction. The combination being finished, the separation of the dyestufi' is completed by adding common salt, the product is then isolated by draining, pressing and drying. It produces on wool from an acid bath clear and intense yellow tints which are more especially very fast to light. The new dye stufl' thus obtained represents in the dry state when pulverized a reddish yellow pow der which dissolves in water to a yellow solution; this aqueous solution on the addition of mncentratcd hydrochloric acid separates the free acid of the dyestufi as yellow- ANY, ASSIGNOR 'ro Specification of Letters Patent. Patented Feb. 21, 1911 Application filedAprll 18, 1910. Serial No. 556,201.

solution which on adding ice 1s partial y pre- I cipitated 'yellow flakes being separated. Furthermore the neutral aqueous solution of the dyestulf when boiled with zine-dust is clecolorized and the solution thus obtained assumes on exposure to air a violet coloration. agents, for instance stanno'us ehlorid and hydrochloric acid, the coloring-matter is split up yielding para-chloranilin-meta-sulfonic acid besides amino-1-phenyl-3-methyl- 5-pyrazolon.

By the action of strong reducing It is obvious to those skilled in the art that my present invention is not limited to -the foregoing example or to the details given therein.

Having now described my invention and the manner in which it may be performed .-.what I claim is,-

As a new article of manufacture the new monoazo-dyestuft' which may be obtained by diazotizing para-ehloranilin-meta-sul fonie acid and combining the diazo-compound thus obtained with l-phenyl-il-mcthyl- 5-pyrazolon, which new dyestufi' produces on wool from an acid bath clear and intense yellow tints of a good fastness which are more especially very fast to light, this new dyestufi' forming in the dry state when pulverized a reddish-yellow powder which is soluble in water to a yellow solution, which solution on the addition of concentrated hydrochloric acid separates the free acid as yellow flakes and which solution on the,

addition of concentrated soda-lye shows a gelatin-like yellow separation, this nevi dyestuti' being soluble in alcohol to a yellow solution and in concentrated sulfuric acid to a greenish-yellow solution which when added with ice is partially precipitated, yellow flakes being separated, and the neutral aqueous solution of this new dyestufl when boiled with zinc-dust being decolorized,

In testimony whereof I have hereunto set my hand 1n presence of two subscrlblng wltwhich decolorized solution on xposure .to air assumes a violet coloration, this new dyestufi being split up by the actionbf strong reducln agents (stanhous chlorid '5 and hydrochlonc acid), thus yieldin parachloranilin meta sul fonic paid insides amino-1-pheny1-3-methyl 5-pyrazo10n. 

